The information in this profile may be out-of-date. It was last revised
in 1996. EXTOXNET no longer updates this information, but it may be useful
as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find
updated pesticide fact sheets.
If you don't find a fact sheet related to
your question, feel free to call 1-800-858-7378.
NPIC is open five days
a week from 8:00am to 12:00pm Pacific Time.

E X T O X N E T

Extension Toxicology
Network

Pesticide Information
Profiles

A Pesticide Information Project of Cooperative Extension
Offices of Cornell University, Oregon State University, the
University of Idaho, and the University of California at Davis
and the Institute for Environmental Toxicology, Michigan State
University. Major support and funding was provided by the
USDA/Extension Service/National Agricultural Pesticide Impact
Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State
University

RegulatoryStatus:
Following a Special Review, the EPA initiated a ban on all
granular formulations of carbofuran which became effective on
September 1, 1994. Before 1991, 80% of the total usage of
carbofuran was in granular formulations. The ban was established
to protect birds and is not related to human health concerns.
Bird kills have occurred when birds ingested carbofuran granules,
which resemble grain seeds and when predatory or scavenging birds
have ingested small birds or mammals which had eaten carbofuran
pellets. There is no ban on liquid formulations of carbofuran.
Liquid formulations of carbofuran are classified as Restricted
Use Pesticides (RUP) because of their acute oral and inhalation
toxicity to humans. Granular formulations are also classified as
RUP's, but for a different reason; their toxicity to birds.
Liquid formulations bear the Signal Word WARNING. Granular
formulations bear the Signal Word DANGER. Formulations of
carbofuran are in toxicity class I - highly toxic or toxicity
class II - moderately toxic.

Chemical Class:
carbamate

Introduction:
Carbofuran is a broad spectrum carbamate pesticide that kills
insects, mites, and nematodes on contact or after ingestion. It
is used against soil and foliar pests of field, fruit, vegetable,
and forest crops. Carbofuran is available in liquid and granular
formulations, but as stated avove the granule form is banned in
the U.S.

Formulation: Carbofuran
is available in liquid and granular formulations, but as stated
above, the granular form is banned in the U.S.

Toxicological Effects:

Acute toxicity: Carbofuran is highly
toxic by inhalation and ingestion and moderately toxic by
dermal absorption [5]. As with other carbamate compounds,
carbofuran's cholinesterase-inhibiting effect is
short-term and reversible [5]. Symptoms of carbofuran
poisoning include: nausea, vomiting, abdominal cramps,
sweating, diarrhea, excessive salivation, weakness,
imbalance, blurring of vision, breathing difficulty,
increased blood pressure, and incontinence. Death may
result at high doses from respiratory system failure
associated with carbofuran exposure [5]. Complete
recovery from an acute poisoning by carbofuran, with no
long-term health effects, is possible if exposure ceases
and the victim has time to regain their normal level of
cholinesterase and to recover from symptoms [5]. The oral
LD50 is 5 to 13 mg/kg in rats, 2 mg/kg in mice, and 19
mg/kg in dogs. The dermal LD50 is >1000 mg/kg in
rabbits, [5]. The LC50 (4-hour) for inhalation of
carbofuran is 0.043 to 0.053 mg/L in guinea pigs [10].

Chronic toxicity: Rats given very high
doses (5 mg/kg/day) for two years showed decreases in
weight. Similar tests with mice gave the same results
[5]. Prolonged or repeated exposure to carbofuran may
cause the same effects as an acute exposure [5].

Reproductive effects: Consuming high
doses over long periods of time caused damage to testes
in dogs, but carbofuran did not have any reproductive
effects on rats or mice [5]. Available studies indicate
carbofuran is unlikely to cause reproductive effects in
humans at expected exposure levels.

Teratogenic effects: Studies indicate
carbofuran is not teratogenic. No significant teratogenic
effects have been found in offspring of rats given
carbofuran (3 mg/kg/day) on days 5 to 19 of gestation. No
effects were found in offspring of mice given as much as
1 mg/kg/day throughout gestation. In rabbits, up to 1
mg/kg/day on days 6 to 18 of gestation was not
teratogenic [5].

Mutagenic effects: Weak or no mutagenic
effects have been reported in animals and bacteria.
Carbofuran is most likely nonmutagenic [5].

Carcinogenic effects: Data from animal
studies indicate that carbofuran does not pose a risk of
cancer to humans [5].

Fate in humans and animals: Carbofuran
is poorly absorbed through the skin [32]. It is
metabolized in the liver and eventually excreted in the
urine. The half-life in the body is from 6 to 12 hours.
Less than 1% of a dose will be excreted in a mother's
milk. It does not accumulate in tissue [5].

Ecological Effects:

Effects on birds: Carbofuran is highly
toxic to birds. One granule is sufficient to kill a small
bird. Bird kills have occurred when birds ingested
carbofuran granules, which resemble grain seeds in size
and shape, or when predatory or scavenging birds have
ingested small birds or mammals that have eaten
carbofuran pellets [33]. Red-shouldered hawks have been
poisoned after eating prey from carbofuran-treated fields
[17]. The LD50 is 0.238 mg/kg in fulvous ducks, 0.48 to
0.51 mg/kg in mallard ducks, 12 mg/kg in bobwhite quail,
and 4.15 mg/kg in pheasant [17]. The LD50 is 25 to 39
mg/kg in chickens consuming carbofuran as a powder [10].
The LC50 (96-hour) in Japanese quail is 746 ppm [34].

Effects on aquatic organisms: Carbofuran
is highly toxic to many fish. The LD50 (96-hour) is 0.38
mg/L in rainbow trout and 0.24 mg/L in bluegill sunfish
[10]. The compound has a low potential to accumulate in
aquatic organisms. The bioconcentration factor ranges
from 10 in snails to over 100 in fish [14].

Effects on other organisms: CArbofuran
is toxic to bees except in the granular formulation [10].

Environmental Fate:

Breakdown in soil and groundwater:
Carbofuran is soluble in water and is moderately
persistent in soil. Its half-life is 30 to 120 days. In
soil, carbofuran is degraded by chemical hydrolysis and
microbial processes. Hydrolysis occurs more rapidly in
alkaline soils [14]. Carbofuran breaks down in sunlight.
Carbofuran has a high potential for groundwater
contamination [14]. Carbofuran is mobile to very mobile
in sandy loam, silty clay, and silty loam soils;
moderately mobile in silty clay loam soils; and only
slightly mobile in muck soils. Small amounts of
carbofuran have been detected (1 to 5 ppb) in water table
aquifers beneath sandy soils in New York and Wisconsin
[14].

Breakdown in water: In water, carbofuran
is subject to degradation by chemical hydrolysis under
alkaline conditions. Photodegradation and aquatic
microbes may also contribute to degradation. The
hydrolysis half-lives of carbofuran in water at 25 C are
690, 8.2, and 1.0 weeks at pH values of 6.0, 7.0, and
8.0, respectively. Carbofuran does not volatilize from
water, nor does it adsorb to sediment or suspended
particles [14].

Breakdown in vegetation: The half-life
of carbofuran on crops is about 4 days when applied to
roots, and longer than 4 days if applied to the leaves
[8].

Physical Properties:

Appearance: Carbofuran is an odorless,
white crystalline solid. Heat breakdown can release toxic
fumes. Fires, and the runoff from fire control, may
produce irritating or poisonous gases. Closed spaces
(storage, etc.) should be aired before entering.

References for the information in this PIP can be found in
Reference List Number 3

DISCLAIMER: The
information in this profile does not in any way replace or
supersede the information on the pesticide product labeling or
other regulatory requirements. Please refer to the pesticide
product labeling.